In many video compression techniques, prediction encoding that is accompanied by motion compensation, that is, inter-prediction (also referred to as inter-frame prediction), has been used. The motion compensation is a technique that includes searching for motion of an object by an encoder, encoding and decoding of a motion vector, and generation of a predicted image based on a motion vector by a decoder. As precision of motion search by the encoder increases, a prediction error decreases, and a higher compression rate can be obtained. The precision of the motion search is restricted by resolution of the motion vector, and the resolution of the motion vector depends on pixel precision of a reference pixel. In a video encoding scheme H.264/AVC, which is a video encoding scheme in the related art, for example, a set of reference pixels with ¼ pixel precision for motion search is generated by using a combination of a 6-tap interpolation filter and linear interpolation. In H.265/HEVC, which is a new video encoding scheme succeeding H.264/AVC, a set of reference pixels with ¼ pixel precision is generated by using an interpolation filter of a maximum of eight taps (see Non-Patent Literature 1).
H.265/HEVC has also specified a method that is called tile division in addition to slice division that has also been employed in H.264/AVC for efficiently compressing a high-resolution video, such as a 4K or 8K video. It becomes easy to encode a video with high resolution or at a high frame rate in real time by processing a certain region (a slice or a tile) and another region in one picture in parallel by separate chips in a multiple-chip processor configuration, for example.